I called 1-800-THE-SHACK as well as all of the local RS stores in my area today, and they were all out of stock. I'd say at this point in time that they're pretty rare, but I'm sure that they'll be back in stock sometime soon (hopefully).
I saw a few of the tuner kits on EBay for even more than that amount (I think one of them was up to $43 or so). Long story short, ain't no way I'll pay that amount (+plus shipping) when sometime in the near future I can get them from my local RS for 12 bucks! -